Image processing apparatus, method, and program

Abstract

A histogram section determines as a motion vector at a pixel of interest the candidate motion vector with highest frequency from among a candidate motion vector at the pixel of interest and candidate motion vectors at pixels neighboring the pixel of interest supplied by a template matching section, and supplies it to a motion-vector correcting section. The motion-vector correction section evaluates the confidence level of the motion vector supplied by the histogram section based on the luminance gradient around the pixel of interest detected by a luminance-gradient detecting section and a control signal indicating whether correction should be carried out supplied by the template matching section. If it is determined that the confidence level of the motion vector is low, the motion vector is corrected.

1 . An image processing apparatus comprising: 
 candidate generating means for setting as a pixel of interest a predetermined pixel from among pixels constituting a first access unit and comparing the first access unit with a second access unit preceding the first access unit to generate a candidate motion vector at the pixel of interest;    motion-vector determining means for determining as a motion vector at the pixel of interest a candidate motion vector with highest frequency from among the candidate motion vector at the pixel of interest and candidate motion vectors at pixels neighboring the pixel of interest generated by the candidate generating means;    luminance-change calculating means for calculating a degree of change in luminance around the pixel of interest; and    correction means for evaluating a confidence level of the motion vector determined by the motion-vector determining means based on results of processing by the luminance-change calculating means and the candidate generating means, and correcting the motion vector if it is determined that the confidence level is low.    
   
   
       2 . The image processing apparatus according to  claim 1 , wherein, if the degree of change in luminance calculated by the luminance-change calculating means is below a threshold, the correction means determines that the confidence level of the motion vector is low and corrects the motion vector.  
   
   
       3 . The image processing apparatus according to  claim 1 , wherein the candidate generating means detects a first pixel on the first access unit as a counterpart pixel for a second pixel on the second access unit, the second pixel being arranged at a location corresponding to the location of the pixel of interest, and generates a vector originating from the pixel of interest and terminating at the first pixel as the candidate motion vector at the pixel of interest.  
   
   
       4 . The image processing apparatus according to  claim 3 , wherein, if it is determined that the first access unit includes a plurality of candidates for the counterpart pixel or that the confidence level of the first pixel being the counterpart pixel is low, the candidate generating means provides the correction means with first information indicating a command for correcting the motion vector; and 
 if the correction means receives the first information from the candidate generating means, the correction means determines that the confidence level of the motion vector is low and corrects the motion vector.    
   
   
       5 . The image processing apparatus according to  claim 4 , wherein, if the pixel of interest is included in the plurality of candidates for the counterpart pixel, the candidate generating means provides the correction means with second information indicating that the pixel of interest is included in the plurality of candidates for the counterpart pixel; and 
 if the correction means receives the second information from the candidate generating means, the correction means determines that the confidence level of the motion vector is low and corrects the motion vector to a 0 vector.    
   
   
       6 . An image processing method comprising: 
 a candidate generating step of setting as a pixel of interest a predetermined pixel from among pixels constituting a first access unit and comparing the first access unit with a second access unit preceding the first access unit to generate a candidate motion vector at the pixel of interest;    a motion-vector determining step of determining as a motion vector at the pixel of interest a candidate motion vector with highest frequency from among the candidate motion vector at the pixel of interest and candidate motion vectors at pixels neighboring the pixel of interest generated in the candidate generating step;    a luminance-change calculating step of calculating a degree of change in luminance around the pixel of interest; and    a correction step of evaluating a confidence level of the motion vector determined in the motion-vector determining step based on results of processing in the luminance-change calculating step and the candidate generating step, and correcting the motion vector if it is determined that the confidence level is low.    
   
   
       7 . A computer-executable program for setting as a pixel of interest a predetermined pixel from among pixels constituting a first access unit and applying image processing to the pixel of interest, the program comprising: 
 a candidate generating step of comparing the first access unit with a second access unit preceding the first access unit to generate a candidate motion vector at the pixel of interest;    a motion-vector determining step of determining as a motion vector at the pixel of interest a candidate motion vector with highest frequency from among the candidate motion vector at the pixel of interest and candidate motion vectors at pixels neighboring the pixel of interest generated in the candidate generating step;    a luminance-change calculating step of calculating a degree of change in luminance around the pixel of interest; and    a correction step of evaluating a confidence level of the motion vector determined in the motion-vector determining step based on results of processing in the luminance-change calculating step and the candidate generating step, and correcting the motion vector if it is determined that the confidence level is low.    
   
   
       8 . An image processing apparatus comprising: 
 candidate generating means for setting as a pixel of interest a predetermined pixel from among pixels constituting a first access unit and comparing the first access unit with a second access unit preceding the first access unit to generate a candidate motion vector at the pixel of interest;    motion-vector determining means for determining as a motion vector at the pixel of interest a candidate motion vector with highest frequency from among the candidate motion vector at the pixel of interest and candidate motion vectors at pixels neighboring the pixel of interest generated by the candidate generating means;    correction means for correcting the motion vector determined by the motion-vector determining means; and    processing executing means for carrying out predetermined processing using the motion vector corrected by the correction means,    wherein the correction means corrects the motion vector by a first method based on a characteristic of the predetermined processing by the processing executing means.    
   
   
       9 . The image processing apparatus according to  claim 8 , further comprising: 
 luminance-change calculating means for calculating a degree of change in luminance around the pixel of interest, wherein the correction means evaluates a confidence level of the motion vector determined by the motion-vector determining means based on results of processing by the luminance-change calculating means and the candidate generating means and, if it is determined that the confidence level of the motion vector is low, further corrects the motion vector corrected by the first method by a second method.    
   
   
       10 . An image processing method by an information processing apparatus, the method comprising: 
 a candidate generating step of setting as a pixel of interest a predetermined pixel from among pixels constituting a first access unit and comparing the first access unit with a second access unit preceding the first access unit to generate a candidate motion vector at the pixel of interest;    a motion-vector determining step of determining as a motion vector at the pixel of interest a candidate motion vector with highest frequency from among the candidate motion vector at the pixel of interest and candidate motion vectors at pixels neighboring the pixel of interest generated in the candidate generating step;    a correction step of correcting the motion vector determined in the motion-vector determining step; and    a processing control step of controlling the information processing apparatus to carry out predetermined processing using the motion vector corrected in the correction step,    wherein, in the correction step, the motion vector is corrected by a correction method based on a characteristic of the predetermined processing by the image processing apparatus in the processing control step.    
   
   
       11 . A computer-executable program for controlling a processing executing apparatus for applying predetermined processing to a predetermined one of a plurality of access units constituting a moving image, wherein the predetermined processing uses a motion vector at each of pixels on the predetermined access unit, the program comprising: 
 a candidate generating step of setting as a pixel of interest a predetermined pixel from among pixels constituting a first access unit and comparing the first access unit with a second access unit preceding the first access unit to generate a candidate motion vector at the pixel of interest;    a motion-vector determining step of determining as a motion vector at the pixel of interest a candidate motion vector with highest frequency from among the candidate motion vector at the pixel of interest and candidate motion vectors at pixels neighboring the pixel of interest generated in the candidate generating step;    a correction step of correcting the motion vector determined in the motion-vector determining step; and    a processing control step of controlling the processing executing apparatus to carry out the predetermined processing using the motion vector corrected in the correction step,    wherein, in the correction step, the motion vector is corrected by a correction method based on a characteristic of the predetermined processing by the processing executing apparatus in the processing control step.    
   
   
       12 . An image processing apparatus comprising: 
 a candidate generating unit for setting as a pixel of interest a predetermined pixel from among pixels constituting a first access unit and comparing the first access unit with a second access unit preceding the first access unit to generate a candidate motion vector at the pixel of interest;    a motion-vector determining unit for determining as a motion vector at the pixel of interest a candidate motion vector with highest frequency from among the candidate motion vector at the pixel of interest and candidate motion vectors at pixels neighboring the pixel of interest generated by the candidate generating unit;    a luminance-change calculating unit for calculating a degree of change in luminance around the pixel of interest; and    a correction unit for evaluating a confidence level of the motion vector determined by the motion-vector determining unit based on results of processing by the luminance-change calculating unit and the candidate generating unit, and correcting the motion vector if it is determined that the confidence level is low.